Boundary conditions for the infinite square well: These slides make the case for the boundary...

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Boundary conditions for the infinite square well: These slides make the case for the boundary conditions for the infinite square well by taking the limit of large well depths for the finite square well. The finite square well wavefunctions were computed using an application found at http://webphysics.davidson.edu/faculty/dm b/SingleWells/Well2.html
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Transcript of Boundary conditions for the infinite square well: These slides make the case for the boundary...

Boundary conditions for the infinite square well:

These slides make the case for the boundary conditions for the infinite square well by taking the limit of large well depths for the finite square well.

The finite square well wavefunctions were computed using an application found at

http://webphysics.davidson.edu/faculty/dmb/SingleWells/Well2.html

Boundary conditions for infinite barrier:

continuous

can be discontinuous at the barrier edge

under the barrier

x

0

Note that the y axis only shows units of energy. No units are show for the wavefunction, which is ok since all that matters is that the probability is normalized to unity.

Boundary conditions for infinite barrier:

continuous

can be discontinuous at the barrier edge

under the barrier

x

0

Intuition about the central barrier

Boundary conditions for infinite barrier:

continuous

can be discontinuous at the barrier edge

under the barrier

x

0

Additional discussion about normalizability

Key point: There exist “energy eigenstates” for the finite square well with continuous values of the eigenvalue E. These states are only excluded by the requirement that the wavefunction be normalizable.

Energy = +36.09

Energy = +36.0901

Energy = +36.0902

Energy = +36.09021

Energy = +36.09022

Energy = +36.09023

Energy = +36.090234

Energy = +36.090235

Energy = +36.090237

Energy = +36.09023772

Energy = +36.090237735

Energy = +36.0902377385

Energy = +36.0902377388

Energy = +36.0902377395

Energy = +36.0902377399

Energy = +36.09023774

Energy = +36.09023775

Energy = +36.09023776

Energy = +36.09023778

Energy = +36.0902378

Energy = +36.0902379

Energy = +36.090238

Energy = +36.090239

Energy = +36.09024

Energy = +36.09025

Energy = +36.09026

Energy = +36.09029

Energy = +36.0904

Energy = +36.0907

Energy = +36.092

Energy = +36.094

Energy = +36.097

Energy = +36.09

Energy = +48

Energy = +55

Energy = +60

Energy = +65

Energy = +70

Energy = +75

Energy = +80

Energy = +81.176